A pivotal day for 2010 elections

A PIVOTAL DAY FOR 2010 ELECTIONS…. We saw some pretty important races four weeks ago, with primaries and a special congressional election in Pennsylvania, Kentucky, and Arkansas. But in light of today’s contests — 11 states are holding primaries today — this Super Tuesday will likely be the biggest days for elections until November.

Let’s take a look at what to watch tonight:

Arkansas

The Democratic runoff Senate primary between Sen. Blanche Lincoln and Lt. Gov. Bill Halter will be decided today, and polls suggest the challenger enjoys the edge. If Lincoln loses, she’ll be the third incumbent senator to fail to qualify for the November ballot, following Utah’s Bob Bennett (R) and Pennsylvania’s Arlen Specter (D).

Nevada

The Republican Senate primary is one of the day’s marquee contests, and former state Rep. Sharron Angle is currently leading former state Republican chairwoman Sue Lowden, who had been considered the prohibitive favorite. Former college basketball player Danny Tarkanian remains in the mix. The ugly primary fight has given Dems renewed hopes about Senate Majority Leader Harry Reid’s (D) re-election prospects.

Nevada will also host a key Republican gubernatorial primary, in which incumbent Gov. Jim Gibbons is expected to fall to former federal judge Brian Sandoval. If Gibbons manages to hold on, Dems have high hopes of winning the governor’s office in November. If Sandoval wins today, not so much.

South Carolina

In one of the year’s more ridiculous, scandal-ridden contests, the Republican gubernatorial primary may be resolved today, with state Rep. Nikki Haley leading a raucous multi-candidate field. If Haley fails to win 50%, there will be a runoff on June 22.

Also keep a close eye on the Republican congressional primary in the 4th District, where incumbent Rep. Bob Inglis (R) is struggling against Spartanburg Solicitor Trey Gowdy, because the GOP base has decided the conservative Inglis may not be right-wing enough.

California

Competitive Republican contests appear likely to be blowouts today, with former Hewlett Packard CEO Carly Fiorina leading former Rep. Tom Campbell and state Rep. Chuck DeVore in the GOP Senate primary. Former eBay CEO Meg Whitman, after spending enormous sums of money, is the clear favorite in the Republicans’ gubernatorial primary over state Insurance Commissioner Steve Poizner.

Also keep an eye on Rep. Jane Harman’s (D) primary fight against Marcy Winograd, who enjoys the support of much of the party’s base.

Iowa

Former Gov. Terry Branstad (R) is trying to get his old job back, and he appears likely to win the GOP primary today, despite right-wing support for Bob Vander Plaats.

Virginia

There’s a great race in the 5th District, where Republicans are choosing a candidate to take on freshman Rep. Tom Perriello. State Sen. Robert Hurt appears to be the favorite, but if Hurt gets the nod, there’s a real possibility that the Tea Partiers will launch an independent campaign.

There are also contests in Maine, Montana, New Jersey, North Dakota, and South Dakota, which should offer nearly endless entertainment for election watchers tonight.